How bad was the life of the urban worker in Victorian Britain?

In The Rational Optimist: How Prosperity Evolves, the contrarian Matt Ridley, who convincingly argues against the dire predictions of Malthus, makes a point that might seem strange to many readers of Victorian novels — namely, that men and women who moved from the country to the noisy, crowded, and polluted city actually most often improved their quality of life:

While it is undoubtedly true that by modern standards the
workers who manned the factories and mills of 1800 in England
laboured for inhuman hours from an early age in conditions of
terrible danger, noise and dirt, returning to crowded and
insanitary homes through polluted streets, and had dreadful job
security, diet, health care and education, it is none the less just
as undeniably true that they lived better lives than their farm-labourer grandfathers and wool-spinning grandmothers had
done. That was why they flocked to the factories from the farms
— and would do so again in New England in the 1870s, in the
American South in the 1900s, in Japan in the 1920s, in Taiwan
in the 1960s, in Hong Kong in the 1970s and in China today.
That was why the jobs in the mills were denied to the Irish in
New England and the blacks in North Carolina.
. . . The economist Pietra Rivoli
writes, 'As generations of mill girls and seamstresses from
Europe, America and Asia are bound together by this common
sweatshop experience — controlled, exploited, overworked, and
underpaid — they are bound together too by one absolute
certainty, shared across both oceans and centuries: this beats the
hell out of life on the farm.'

If one accepts Ridley's argument that the average person, even women working in factories, enjoyed a better life in the city than they had in the country — not because the often-described working conditions did not exist but that they nonetheless were better than those of the country laborer — the question remains: why do we and the Victorians before us so emphasize the poverty and living conditions of the urban poor?

The reason that the poverty of early industrial England strikes
us so forcibly is that this was the first time writers and politicians
took notice of it and took exception to it, not because it had not
existed before. Mrs Gaskell and Mr Dickens had no equivalents
in previous centuries; factory acts and child labour restrictions
were unaffordable before. The industrial revolution caused a
leap in the wealth-generating capacity of the population that
greatly outstripped its breeding potential but it thereby also
caused an increase in compassion, much of which was expressed
through the actions of charities and governments. [219-220]

Ridley is correct on two important points and a bit misleading on another. Yes,
Gaskell and Dickens were among the first of many to thrust the poverty of the manufacturing and urban poor in the faces of the reader, and they did so not only because they had an audience willing to read such criticisms of their own society but also because the largest part of their readers did not come from the ideal wealthy upper-middle and upper-class reader of the Augustan age. But since Ridley mentions the social protests of nineteenth-century authors in the midst of his arguments against those who mistakenly believe that farm workers had better living and working conditions than those in factory towns, he implies that both authors (1) had too rosy a view of rural life and (2) considered it superior to life in the city. In fact, neither novelist compared life of the rural poot favorably to to that of the factory worker, and Gaskell's North and South specifically attacks that misconception. Her protagonist, Margaret Hale, who initially finds herself devastated by having to leave a beautiful country parsonage and move to Milton, a grimy factory town modelled after Manchester, by the second half of the novel "stands up for progress" and tells Nicolas Higgins, the desperate unemployed textile worker

I owe it to you — since it's my way of talking that has set you off on this idea — to put it all clear before you. You would not bear the dullness of the life; you don't know what it is; it would eat you away like rust. Those that have lived there all their lives, are used to soaking in the stagnant waters. They labor on from day to da, in the great solitude of steaming fields — never lifting up their poor, bent, downcast heads. The hard spadework robs them of their brain of life; the sameness of their toil deadens their imagination. . . . they go home brutishly tired, poor creatures! caring for nothing but food and rest. [Chapter 37]

As Gaskell shows, at least some major Victorian novelists correctly gauged the wretched conditions of life in England's rural areas, and they clearly understood that as bad as was life in the industrial city, it represented a major improvement on rural existence. Nonetheless, that improvement of their quality of life was no reason to accept the still-miserable conditions in which many of the urban poor found themselves.